The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions

Objectives: Irritating effects of organic solvents have usually been measur ed by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating e ffects. Methods: Twelve healthy, non-smoking students were exposed to 200 p pm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a cros sover design. The amounts of interleukins (IL)-1 beta, IL-6 and IL-8 and pr ostaglandin E-2 (PGE(2)) in nasal secretions were measured. Mucociliary tra nsport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast mi croscopy. Subjective symptoms were assessed by questionnaire. Results: Conc entrations of ILs were significantly elevated after exposure to 200 ppm 1,1 ,1-trichloroethane (IL-1 beta 82.4 vs. 28.8 pg/ml (medians), P = 0.003; IL- 6 12.2 vs. 7.2 pg/ml, P = 0.01; IL-8 549 vs. 424 pg/ml, P = 0.007), whereas the other parameters remained unchanged. Conclusion: The interleukins meas ured proved to be sensitive indicators of irritating effects of 1,1,1-trich loroethane. The German threshold limit (MAK value) of 200 ppm 1,1,1-trichlo roethane does not prevent the subclinical inflammation of nasal mucosa.